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// Copyright (C) 2009-2024 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef NAME_H
#define NAME_H
#include <util/buffer.h>
#include <dns/messagerenderer.h>
#include <stdint.h>
#include <string>
#include <vector>
#include <dns/exceptions.h>
namespace isc {
namespace dns {
///
/// \brief A standard DNS module exception that is thrown if the name parser
/// encounters an empty label in the middle of a name.
///
class EmptyLabel : public NameParserException {
public:
EmptyLabel(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
///
/// \brief A standard DNS module exception that is thrown if the name parser
/// encounters too long a name.
///
class TooLongName : public NameParserException {
public:
TooLongName(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
///
/// \brief A standard DNS module exception that is thrown if the name parser
/// encounters too long a label.
///
class TooLongLabel : public NameParserException {
public:
TooLongLabel(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
///
/// \brief A standard DNS module exception that is thrown if the name parser
/// encounters an obsolete or incomplete label type. In effect "obsolete" only
/// applies to bitstring labels, which would begin with "\[". Incomplete cases
/// include an incomplete escaped sequence such as "\12".
///
class BadLabelType : public NameParserException {
public:
BadLabelType(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
///
/// \brief A standard DNS module exception that is thrown if the name parser
/// fails to decode a back-slash escaped sequence.
///
class BadEscape : public NameParserException {
public:
BadEscape(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
///
/// \brief A standard DNS module exception that is thrown if the name parser
/// finds the input (string or wire-format %data) is incomplete.
///
/// An attempt of constructing a name from an empty string will trigger this
/// exception.
///
class IncompleteName : public NameParserException {
public:
IncompleteName(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
/// \brief Thrown when origin is null and is needed.
///
/// The exception is thrown when the Name constructor for master file
/// is used, the provided data is relative and the origin parameter is
/// set to null.
class MissingNameOrigin : public NameParserException {
public:
MissingNameOrigin(const char* file, size_t line, const char* what) :
NameParserException(file, line, what) {}
};
///
/// This is a supplemental class used only as a return value of
/// Name::compare() and LabelSequence::compare().
/// It encapsulate a tuple of the comparison: ordering, number of common
/// labels, and relationship as follows:
/// - ordering: relative ordering under the DNSSEC order relation
/// - labels: the number of common significant labels of the two names or
/// two label sequences being compared
/// - relationship: see NameComparisonResult::NameRelation
///
/// Note that the ordering is defined for two label sequences that have no
/// hierarchical relationship (in which case the relationship will be NONE).
/// For example, two non absolute (or "relative") sequences "example.com" and
/// "example.org" have no hierarchical relationship, and the former should be
/// sorted before (i.e. "smaller") than the latter.
class NameComparisonResult {
public:
/// The relation of two names under comparison.
/// Its semantics for the case of
/// <code>name1->compare(name2)</code> (where name1 and name2 are instances
/// of the \c Name or \c LabelSequence class) is as follows:
/// - SUPERDOMAIN: name1 properly contains name2; name2 is a proper
/// subdomain of name1
/// - SUBDOMAIN: name1 is a proper subdomain of name2
/// - EQUAL: name1 and name2 are equal
/// - COMMONANCESTOR: name1 and name2 share a common ancestor
/// - NONE: There's no hierarchical relationship between name1 and name2
///
/// Note that there's always a hierarchical relationship between any two
/// names since all names (not generic label sequences) are absolute and
/// they at least share the trailing empty label.
/// So, for example, the relationship between "com." and "net." is
/// "commonancestor". The relationship of "NONE" can only happen for
/// comparison between two label sequences (\c LabelSequence objects);
/// usually only SUPERDOMAIN, SUBDOMAIN or EQUAL are important relationship
/// between two names.
///
/// When two \c LabelSequence objects are compared, it's generally expected
/// they are either both absolute or both non absolute; if one is absolute
/// and the other is not, the resulting relationship will be NONE.
enum NameRelation {
SUPERDOMAIN = 0,
SUBDOMAIN = 1,
EQUAL = 2,
COMMONANCESTOR = 3,
NONE = 4
};
///
/// \name Constructors and Destructor
///
//@{
/// \brief Constructor from a comparison tuple
///
/// This constructor simply initializes the object in the straightforward
/// way.
NameComparisonResult(int order, unsigned int nlabels,
NameRelation relation) :
order_(order), nlabels_(nlabels), relation_(relation) {}
//@}
///
/// \name Getter Methods
///
//@{
/// Returns the ordering of the comparison result
int getOrder() const { return (order_); }
/// Returns the number of common labels of the comparison result
unsigned int getCommonLabels() const { return (nlabels_); }
/// Returns the NameRelation of the comparison result
NameRelation getRelation() const { return (relation_); }
//@}
private:
int order_;
unsigned int nlabels_;
NameRelation relation_;
};
///
/// The \c Name class encapsulates DNS names.
///
/// It provides interfaces to construct a name from string or wire-format %data,
/// transform a name into a string or wire-format %data, compare two names, get
/// access to various properties of a name, etc.
///
/// Notes to developers: Internally, a name object maintains the name %data
/// in wire format as an instance of \c std::string. Since many string
/// implementations adopt copy-on-write %data sharing, we expect this approach
/// will make copying a name less expensive in typical cases. If this is
/// found to be a significant performance bottleneck later, we may reconsider
/// the internal representation or perhaps the API.
///
/// A name object also maintains a vector of offsets (\c offsets_ member),
/// each of which is the offset to a label of the name: The n-th element of
/// the vector specifies the offset to the n-th label. For example, if the
/// object represents "www.example.com", the elements of the offsets vector
/// are 0, 4, 12, and 16. Note that the offset to the trailing dot (16) is
/// included. In the BIND9 DNS library from which this implementation is
/// derived, the offsets are optional, probably due to performance
/// considerations (in fact, offsets can always be calculated from the name
/// %data, and in that sense are redundant). In our implementation, however,
/// we always build and maintain the offsets. We believe we need more low
/// level, specialized %data structure and interface where we really need to
/// pursue performance, and would rather keep this generic API and
/// implementation simpler.
///
/// While many other DNS APIs introduce an "absolute or relative"
/// attribute of names as defined in RFC1035, names are always "absolute" in
/// the initial design of this API.
/// In fact, separating absolute and relative would confuse API users
/// unnecessarily. For example, it's not so intuitive to consider the
/// comparison result of an absolute name with a relative name.
/// We've looked into how the concept of absolute names is used in BIND9,
/// and found that in many cases names are generally absolute.
/// The only reasonable case of separating absolute and relative is in a master
/// file parser, where a relative name must be a complete name with an "origin"
/// name, which must be absolute. So, in this initial design, we chose a
/// simpler approach: the API generally handles names as absolute; when we
/// introduce a parser of master files, we'll introduce the notion of relative
/// names as a special case.
///
class Name {
// LabelSequences use knowledge about the internal data structure
// of this class for efficiency (they use the offsets_ vector and
// the ndata_ string)
friend class LabelSequence;
///
/// \name Constructors and Destructor
///
//@{
private:
/// \brief Name data string
typedef std::vector<uint8_t> NameString;
/// \brief Name offsets type
typedef std::vector<uint8_t> NameOffsets;
/// The default constructor
///
/// This is used internally in the class implementation, but at least at
/// the moment defined as private because it will construct an incomplete
/// object in that it doesn't have any labels. We may reconsider this
/// design choice as we see more applications of the class.
Name() : length_(0), labelcount_(0) {}
public:
/// Constructor from a string
///
/// If the given string does not represent a valid DNS name, an exception
/// of class \c EmptyLabel, \c TooLongLabel, \c BadLabelType, \c BadEscape,
/// \c TooLongName, or \c IncompleteName will be thrown.
/// In addition, if resource allocation for the new name fails, a
/// corresponding standard exception will be thrown.
///
/// \param namestr A string representation of the name to be constructed.
/// \param downcase Whether to convert upper case alphabets to lower case.
explicit Name(const std::string& namestr, bool downcase = false);
/// \brief Constructor for master file parser
///
/// This acts similar to the above. But the data is passed as raw C-string
/// instead of wrapped-up C++ std::string.
///
/// Also, when the origin is non-null and the name_data is not ending with
/// a dot, it is considered relative and the origin is appended to it.
///
/// If the name_data is equal to "@", the content of origin is copied.
///
/// \param name_data The raw data of the name.
/// \param data_len How many bytes in name_data is valid and considered
/// part of the name.
/// \param origin If non-null, it is taken as the origin to complete
/// relative names.
/// \param downcase Whether to convert upper case letters to lower case.
/// \throw NameParserException or any of its descendants in case the
/// input data is invalid.
/// \throw isc::InvalidParameter In case name_data is null or
/// data_len is 0.
/// \throw std::bad_alloc In case allocation fails.
/// \note This constructor is specially designed for the use of master
/// file parser. It mimics the behaviour of names in the master file
/// and accepts raw data. It is not recommended to be used by anything
/// else.
/// \todo Should we make it private and the parser a friend, to hide the
/// constructor?
Name(const char* name_data, size_t data_len, const Name* origin,
bool downcase = false);
/// Constructor from wire-format %data.
///
/// The \c buffer parameter normally stores a complete DNS message
/// containing the name to be constructed. The current read position of
/// the buffer points to the head of the name.
///
/// The input %data may or may not be compressed; if it's compressed, this
/// method will automatically decompress it.
///
/// If the given %data does not represent a valid DNS name, an exception
/// of class \c DNSMessageFORMERR will be thrown.
/// In addition, if resource allocation for the new name fails, a
/// corresponding standard exception will be thrown.
///
/// \param buff A buffer storing the wire format %data.
/// \param downcase Whether to convert upper case alphabets to lower case.
explicit Name(isc::util::InputBuffer& buff, bool downcase = false);
///
/// We use the default copy constructor intentionally.
//@}
/// We use the default copy assignment operator intentionally.
///
///
/// \name Getter Methods
///
//@{
/// \brief Provides one-byte name %data in wire format at the specified
/// position.
///
/// This method returns the unsigned 8-bit value of wire-format \c Name
/// %data at the given position from the head.
///
/// For example, if \c n is a \c Name object for "example.com",
/// \c n.at(3) would return \c 'a', and \c n.at(7) would return \c 'e'.
/// Note that \c n.at(0) would be 7 (decimal), the label length of
/// "example", instead of \c 'e', because it returns a %data portion
/// in wire-format. Likewise, \c n.at(8) would return 3 (decimal)
/// instead of <code>'.'</code>
///
/// This method would be useful for an application to examine the
/// wire-format name %data without dumping the %data into a buffer,
/// which would involve %data copies and would be less efficient.
/// One common usage of this method would be something like this:
/// \code for (size_t i = 0; i < name.getLength(); ++i) {
/// uint8_t c = name.at(i);
/// // do something with c
/// } \endcode
///
/// Parameter \c pos must be in the valid range of the name %data, that is,
/// must be less than \c Name.getLength(). Otherwise, an exception of
/// class \c OutOfRange will be thrown.
/// This method never throws an exception in other ways.
///
/// \param pos The position in the wire format name %data to be returned.
/// \return An unsigned 8-bit integer corresponding to the name %data
/// at the position of \c pos.
uint8_t at(size_t pos) const
{
if (pos >= length_) {
isc_throw(OutOfRange, "Out of range access in Name::at()");
}
return (ndata_[pos]);
}
/// \brief Gets the length of the <code>Name</code> in its wire format.
///
/// This method never throws an exception.
///
/// \return the length (the number of octets in wire format) of the
/// <code>Name</code>
size_t getLength() const { return (length_); }
/// \brief Returns the number of labels contained in the <code>Name</code>.
///
/// Note that an empty label (corresponding to a trailing '.') is counted
/// as a single label, so the return value of this method must be >0.
///
/// This method never throws an exception.
///
/// \return the number of labels
unsigned int getLabelCount() const { return (labelcount_); }
//@}
///
/// \name Converter methods
///
//@{
/// \brief Convert the Name to a string.
///
/// This method returns a <code>std::string</code> object representing the
/// Name as a string. Unless <code>omit_final_dot</code> is
/// <code>true</code>, the returned string ends with a dot '.'; the default
/// is <code>false</code>. The default value of this parameter is
/// <code>true</code>; converted names will have a trailing dot by default.
///
/// This function assumes the name is in proper uncompressed wire format.
/// If it finds an unexpected label character including compression pointer,
/// an exception of class \c BadLabelType will be thrown.
/// In addition, if resource allocation for the result string fails, a
/// corresponding standard exception will be thrown.
//
/// \param omit_final_dot whether to omit the trailing dot in the output.
/// \return a string representation of the <code>Name</code>.
std::string toText(bool omit_final_dot = false) const;
/// \brief Convert the LabelSequence to a string without escape sequences.
///
/// The string returned will contain a single character value for any
/// escape sequences in the label(s).
///
/// \param omit_final_dot whether to omit the trailing dot in the output.
/// \return a string representation of the <code>LabelSequence</code>
/// that does not contain escape sequences. Default value is false.
std::string toRawText(bool omit_final_dot = false) const;
/// \brief Render the <code>Name</code> in the wire format with compression.
///
/// This method dumps the Name in wire format with help of \c renderer,
/// which encapsulates output buffer and name compression algorithm to
/// render the name.
///
/// If resource allocation in rendering process fails, a corresponding
/// standard exception will be thrown.
///
/// \param renderer DNS message rendering context that encapsulates the
/// output buffer and name compression information.
void toWire(AbstractMessageRenderer& renderer) const;
/// \brief Render the <code>Name</code> in the wire format without
/// compression.
///
/// If resource allocation in rendering process fails, a corresponding
/// standard exception will be thrown. This can be avoided by preallocating
/// a sufficient size of \c buffer. Specifically, if
/// <code>buffer.getCapacity() - buffer.getLength() >= Name::MAX_WIRE</code>
/// then this method should not throw an exception.
///
/// \param buff An output buffer to store the wire %data.
void toWire(isc::util::OutputBuffer& buff) const;
//@}
///
/// \name Comparison methods
///
//@{
/// \brief Compare two <code>Name</code>s.
///
/// This method compares the <code>Name</code> and <code>other</code> and
/// returns the result in the form of a <code>NameComparisonResult</code>
/// object.
///
/// Note that this is case-insensitive comparison.
///
/// This method never throws an exception.
///
/// \param other the right-hand operand to compare against.
/// \return a <code>NameComparisonResult</code> object representing the
/// comparison result.
NameComparisonResult compare(const Name& other) const;
public:
/// \brief Return true iff two names are equal.
///
/// Semantically this could be implemented based on the result of the
/// \c compare() method, but the actual implementation uses different code
/// that simply performs character-by-character comparison (case
/// insensitive for the name label parts) on the two names. This is because
/// it would be much faster and the simple equality check would be pretty
/// common.
///
/// This method never throws an exception.
///
/// \param other the <code>Name</code> object to compare against.
/// \return true if the two names are equal; otherwise false.
bool equals(const Name& other) const;
/// Same as equals()
bool operator==(const Name& other) const { return (equals(other)); }
/// \brief Return true iff two names are not equal.
///
/// This method simply negates the result of \c equal() method, and in that
/// sense it's redundant. The separate method is provided just for
/// convenience.
bool nequals(const Name& other) const { return (!(equals(other))); }
/// Same as nequals()
bool operator!=(const Name& other) const { return (nequals(other)); }
/// \brief Less-than or equal comparison for Name against <code>other</code>
///
/// The comparison is based on the result of the \c compare() method.
///
/// This method never throws an exception.
///
/// \param other the <code>Name</code> object to compare against.
/// \return true if <code>compare(other).getOrder() <= 0</code>;
/// otherwise false.
bool leq(const Name& other) const;
/// Same as leq()
bool operator<=(const Name& other) const { return (leq(other)); }
/// \brief Greater-than or equal comparison for Name against
/// <code>other</code>
///
/// The comparison is based on the result of the \c compare() method.
///
/// This method never throws an exception.
///
/// \param other the <code>Name</code> object to compare against.
/// \return true if <code>compare(other).getOrder() >= 0</code>;
/// otherwise false.
bool geq(const Name& other) const;
/// Same as geq()
bool operator>=(const Name& other) const { return (geq(other)); }
/// \brief Less-than comparison for Name against <code>other</code>
///
/// The comparison is based on the result of the \c compare() method.
///
/// This method never throws an exception.
///
/// \param other the <code>Name</code> object to compare against.
/// \return true if <code>compare(other).getOrder() < 0</code>;
/// otherwise false.
bool lthan(const Name& other) const;
/// Same as lthan()
bool operator<(const Name& other) const { return (lthan(other)); }
/// \brief Greater-than comparison for Name against <code>other</code>
///
/// The comparison is based on the result of the \c compare() method.
////
/// This method never throws an exception.
///
/// \param other the <code>Name</code> object to compare against.
/// \return true if <code>compare(other).getOrder() > 0</code>;
/// otherwise false.
bool gthan(const Name& other) const;
/// Same as gthan()
bool operator>(const Name& other) const { return (gthan(other)); }
//@}
///
/// \name Transformer methods
///
//@{
/// \brief Extract a specified subpart of Name.
///
/// <code>name.split(first, n)</code> constructs a new name starting from
/// the <code>first</code>-th label of the \c name, and subsequent \c n
/// labels including the \c first one. Since names in this current
/// implementation are always "absolute", if the specified range doesn't
/// contain the trailing dot of the original \c name, then a dot will be
/// appended to the resulting name. As a result, the number of labels
/// will be <code>n + 1</code>, rather than \c n. For example,
/// when \c n is <code>Name("www.example.com")</code>,
/// both <code>n.split(1, 2)</code> and <code>n.split(1, 3)</code>
/// will produce a name corresponding to "example.com.", which has 3 labels.
/// Note also that labels are counted from 0, and so <code>first = 1</code>
/// in this example specified the label "example", not "www".
///
/// Parameter \c n must be larger than 0, and the range specified by
/// \c first and \c n must not exceed the valid range of the original name;
/// otherwise, an exception of class \c OutOfRange will be thrown.
///
/// Note to developers: we may want to have different versions (signatures)
/// of this method. For example, we want to split the Name based on a given
/// suffix name.
///
/// \param first The start position (in labels) of the extracted name
/// \param n Number of labels of the extracted name
/// \return A new Name object based on the Name containing <code>n</code>
/// labels including and following the <code>first</code> label.
Name split(unsigned int first, unsigned int n) const;
/// \brief Extract a specified super domain name of Name.
///
/// This function constructs a new \c Name object that is a super domain
/// of \c this name.
/// The new name is \c level labels upper than \c this name.
/// For example, when \c name is www.example.com,
/// <code>name.split(1)</code> will return a \c Name object for example.com.
/// \c level can be 0, in which case this method returns a copy of
/// \c this name.
/// The possible maximum value for \c level is
/// <code>this->getLabelCount()-1</code>, in which case this method
/// returns a root name.
///
/// One common expected usage of this method is to iterate over super
/// domains of a given name, label by label, as shown in the following
/// sample code:
/// \code // if name is www.example.com...
/// for (int i = 0; i < name.getLabelCount(); ++i) {
/// Name upper_name(name.split(i));
/// // upper_name'll be www.example.com., example.com., com., and then .
/// }
/// \endcode
///
/// \c level must be smaller than the number of labels of \c this name;
/// otherwise an exception of class \c OutOfRange will be thrown.
/// In addition, if resource allocation for the new name fails, a
/// corresponding standard exception will be thrown.
///
/// Note to developers: probably as easily imagined, this method is a
/// simple wrapper to one usage of the other
/// <code>split(unsigned int, unsigned int) const</code> method and is
/// redundant in some sense.
/// We provide the "redundant" method for convenience, however, because
/// the expected usage shown above seems to be common, and the parameters
/// to the other \c split(unsigned int, unsigned int) const to implement
/// it may not be very intuitive.
///
/// We are also aware that it is generally discouraged to add a public
/// member function that could be implemented using other member functions.
/// We considered making it a non member function, but we could not come
/// up with an intuitive function name to represent the specific service.
/// Some other developers argued, probably partly because of the
/// counter intuitive function name, a different signature of \c split
/// would be better to improve code readability.
/// While that may be a matter of personal preference, we accepted the
/// argument. One major goal of public APIs like this is wider acceptance
/// from internal/external developers, so unless there is a clear advantage
/// it would be better to respect the preference of the API users.
///
/// Since this method doesn't have to be a member function in other way,
/// it is intentionally implemented only using public interfaces of the
/// \c Name class; it doesn't refer to private members of the class even if
/// it could.
/// This way we hope we can avoid damaging the class encapsulation,
/// which is a major drawback of public member functions.
/// As such if and when this "method" has to be extended, it should be
/// implemented without the privilege of being a member function unless
/// there is a very strong reason to do so. In particular a minor
/// performance advantage shouldn't justify that approach.
///
/// \param level The number of labels to be removed from \c this name to
/// create the super domain name.
/// (0 <= \c level < <code>this->getLabelCount()</code>)
/// \return A new \c Name object to be created.
Name split(unsigned int level) const;
/// \brief Reverse the labels of a name
///
/// This method reverses the labels of a name. For example, if
/// \c this is "www.example.com.", this method will return
/// "com.example.www." (This is useful because DNSSEC sort order
/// is equivalent to a lexical sort of label-reversed names.)
Name reverse() const;
/// \brief Concatenate two names.
///
/// This method appends \c suffix to \c this Name. The trailing dot of
/// \c this Name will be removed. For example, if \c this is "www."
/// and \c suffix is "example.com.", a successful return of this method
/// will be a name of "www.example.com."
///
///The resulting length of the concatenated name must not exceed
/// \c Name::MAX_WIRE; otherwise an exception of class
/// \c TooLongName will be thrown.
///
/// \param suffix a Name object to be appended to the Name.
/// \return a new Name object concatenating \c suffix to \c this Name.
Name concatenate(const Name& suffix) const;
/// \brief Downcase all upper case alphabet characters in the name.
///
/// This method modifies the calling object so that it can perform the
/// conversion as fast as possible and can be exception free.
///
/// The return value of this version of \c downcase() is a reference to
/// the calling object (i.e., \c *this) so that the caller can use the
/// result of downcasing in a single line. For example, if variable
/// \c n is a \c Name class object possibly containing upper case
/// characters, and \c b is an \c OutputBuffer class object, then the
/// following code will dump the name in wire format to \c b with
/// downcasing upper case characters:
///
/// \code n.downcase().toWire(b); \endcode
///
/// Since this method modifies the calling object, a \c const name object
/// cannot call it. If \c n is a \c const Name class object, it must first
/// be copied to a different object and the latter must be used for the
/// downcase modification.
///
/// \return A reference to the calling object with being downcased.
Name& downcase();
//@}
///
/// \name Testing methods
///
//@{
/// \brief Test if this is a wildcard name.
///
/// \return \c true if the least significant label of this Name is
/// <code>'*'</code>; otherwise \c false.
bool isWildcard() const;
//@}
///
/// \name Protocol constants
///
//@{
/// \brief Max allowable length of domain names.
static const size_t MAX_WIRE = 255;
/// \brief Max allowable labels of domain names.
///
/// This is <code>ceil(MAX_WIRE / 2)</code>, and is equal to the number of
/// labels of name "a.a.a.a....a." (127 "a"'s and trailing dot).
static const size_t MAX_LABELS = 128;
/// \brief Max allowable length of labels of a domain name.
static const size_t MAX_LABELLEN = 63;
/// \brief Max possible pointer value for name compression.
///
/// This is the highest number of 14-bit unsigned integer. Name compression
/// pointers are identified as a 2-byte value starting with the upper two
/// bit being 11.
static const uint16_t MAX_COMPRESS_POINTER = 0x3fff;
/// \brief A 8-bit masked value indicating a start of compression pointer.
static const uint16_t COMPRESS_POINTER_MARK8 = 0xc0;
/// \brief A 16-bit masked value indicating a start of compression pointer.
static const uint16_t COMPRESS_POINTER_MARK16 = 0xc000;
//@}
///
/// \name Well-known name constants
///
//@{
/// \brief Root name (i.e. ".").
static const Name& ROOT_NAME();
//@}
private:
NameString ndata_;
NameOffsets offsets_;
unsigned int length_;
unsigned int labelcount_;
};
inline const Name&
Name::ROOT_NAME() {
static Name root_name(".");
return (root_name);
}
///
/// \brief Insert the name as a string into stream.
///
/// This method convert the \c name into a string and inserts it into the
/// output stream \c os.
///
/// This function overloads the global operator<< to behave as described in
/// ostream::operator<< but applied to \c Name objects.
///
/// \param os A \c std::ostream object on which the insertion operation is
/// performed.
/// \param name The \c Name object output by the operation.
/// \return A reference to the same \c std::ostream object referenced by
/// parameter \c os after the insertion operation.
std::ostream&
operator<<(std::ostream& os, const Name& name);
}
}
#endif // NAME_H